Jose Julian Barrera was born circa 1770, the son of Ignacio Barrera and Manuela Flores.
In 1782, he lived in Mier. The church census recorded that he was a child, español, and 12 years old. His household included 6 people:
Juan Jose Ygnacio Barrera, español, married, age 37.
Manuela Flores, española, married, age 28.
Jose Julian Barrera, español, a child, age 12.
Jose Manuel Barrera, español, a child, age 10.
Maria Caterina Barrera, española, a child, age 5.
Maria Luisa Hinojosa, española, a widow, age 55.